Telephone system.



A. H. DYSON.

TELEPHONE SYSTEM.

APPLICATION FILED MAR. 31, 1914.

1,167,053, Patented Jun. 4, 1916.

2 SHEETSSHEET I.

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A.'H. DYSON.

v TELEPHONE SYSTEM.

APPLICATION FILED MAR- 31, l9l4. 1,167,053. Patented Jan. 4, 1916.

. 2 SHEETS-SHEET 2.

WY/ 5352 /nvenf0/ X W A/fl ed H. Dyson.

X AW UNITED "STATES PATENT oEEIoE.

ALFRED H. DYSO'N, OF MONTCLAIR, NEW JERSEY, ASSIG-NOR, BY MESNE ASSIGN- MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OE NEW YORK.

To all whom it may concern:

Be it known that I. ALFRED HARTWELL DYsoN, a citizen of the United States, residin at Montclair, in the county of Essex and tate'of New Jersey, have invented a certain new and.- useful Improvement in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates phone systems. 7 I The invention is applied to a system in which automatic connecting switches 10- catedat a central oflice are controlled over two line wires leading to a subscribers station without the aid of a third conductor.

The object of this invention is to provide means for variously controlling the switches to automatic teleof the system over these two line conductors. The particular classes of control here provided for are the movement of the .contacts of a switch to a desired position, the maintenance of the switch in thisdesired position during the control of other switches and thg return of the switch to its normal position. The means by which the foregoing controls are accomplished is a timed switching device which serves to alter circuit conditions after the lapse of a predetermined interval, which interval is of suflicient duration to permit the sending of the greatest number of directive impulses which is required for 'moving any switch to its last position. The apparatus for accomplishing this control comprises an escapement mechanism which is electrically set and timed to the desired interval by the selection of parts of the proper dimensions and inertia. The invention is illustrated in the accompanying drawings in which Figure 1 is a right handelevation of this mechanism; Fig. 3 is a front elevation of this mechanism; Fig. 4 is a perspective view of part of this mechanism; and Fig. 5 is a circuit diagram showing the portion of a telephone system in which this mechanism is used.

The mechanism of Figs. 1, 2, 3 and 4 comprises a base plate 1, which has a plurality of supporting projections formed thereof and bent so as to extend outwardly at right angles to the main plate. Between two of Specification of Letters Patent.

-10 between a pairof supports is a plan of the mechanism for 1 obtaining the desired time interval; 2"

til the lever 14 TELEPHONE SYSTEM. p i

PatentedJ-an. 4, 1916.

Application filed March 31, 1914. Serial No. 828,585. 4

is pivoted. Loosely mounted upon the shaft 2 is a pinion. gear 6, which carries a dog 7 adapted to engage the single tooth in the ratchet wheel 5. Connected between the pinion gear 6 and the frame of the device is a coil spring 8 tending to rotate said pinion gear 6 in a clockwise direction. Meshmg with the pinion wheel 6 is a rack .9 supported upon an arm 14, which is pivoted at utwardly from the plate 1, This rack is of sufficient length that in its movement about its pivotal point 10, the pinion gear 6 is given slightly over one complete revolution, Upon the return of the rack and pinion wheel mder the influence of spring 8, the dog 7 ratchet 5 and thus carries the shaft 2 one revolution in a clockwise direction. Meshing with the gear wheel 4 is a pinion 11 carr ed upon a shaft upon which is also carried the scape wheel 12, which is engaged by the pallet 13 to cause a slow return movement of shaft spring 8.

An electromagnet 15 is arranged to act upon an armature 16 which is attached to the pivoted arm, 14 carrying rack 9, the arrangement being such that the pull of the magnet upon its armature moves the arm 14 in a clockwise direction about the pivot 10.

Attached to the rack supporting lever 14 is a pivotedmember 17, which, by means of spring 18, is pressed against the forward end of contact spring-19. 'The member 17 has a projection 20 formed thereon which has inclined faces engaging'the end of contact spring 19. In the clockwise movement of'the lever 14, the contact spring 19 is held against its mate 21, but at the completion of the stroke of the lever 14, the peak of 2 under the influence of extending engages the single projection upon the projection 20 is pushed past the end of the contact spring 19, whereupon the spring is forced armature 16, whereas 1t is opened from its mate during the entire receding movement of said armature.

A set of 'springs 22, 23 and '24 is controlled by the cam 3, the movable'spring.

momentary contact between springs 23 and 22 is completed.

In Fig. 5, of the parts just described, appear those designated by the numerals 15, 19, 21, 22, 23 and 24. In this figure the calling subscribers station 30 is provided with the usual transmitter and receiver and with a controlling device having contacts 31 arranged to open the circuit of the lineconductors 32 and 33 in the transmission ofa signal. This line isconnected through suitable switch contacts with the conductors of a selector switch circuitwherein the line conductor 32 extends through one winding of relay 34 to the live pole of central battery 35, and line conductor 33 extends through another winding of relay 34 to the ground.

pole of said battery. The preliminary closurerof the line at the subscribers station by the removal of the subscribers receiver from its hook, energizes relay 34, causing the closure of its front contacts 36 and the consequent energization of relay 37. The energization of relay 37 completes a local circuit for itself through its front'contact 38 and the normal contacts between springs 23 and 24, this circuit including the impedance 39.

A series of short interruptions is now produced by means of the circuit breaker 31 at the subscribers station 30, the number of interruptions depending upon the number,

of the desired subscribers telephone, and being in all events equal in number to'one of I the digits of the desired subscribers numher. At the first interruption the relay 34 releases its armatures. The first release completes a circuit through back contacts 40 of'relay 34, front contacts 41 of relay 37, contacts 19 and 21 and the coil of electro-- magnet 15, this circuit including the. battery 35. Electromagnet 15 thereupon pulls in its armature 16, moving the arm 14 and rack 9 in a clockwise direction, and finally opening contacts 19 and 21 at the extreme position of the rack. The shaft 2 immediately starts in its revolution under the influence of spring 8. At each deenergization of relay 34, the back contacts 42 of that relay complete a circuit through front contacts 43 of relay 37, conductor 44, contacts 45 and the coil of preliminary stepping magnet 46 to battery. Current in this path energizes the stepping magnet 46 once for each time that memes the circuit isiinterrupted at subscribers station 30. The switch controlled in its pri -mary movement by stepping magnet 46 is of a type in. which each-deenergization and deenergization jiof-izthe' primary magnet: '46

moves a set otcontactwipers in front of a group or a rowjotcon'tactsfthus one enerf gization of the primary magnet 46 places the wipers in front of one group of the 'contacts, two energizations and deenergizations in front of another-and so pn, the number of groups usually being ten.

The pallet 13 -'s so constructed that the I time required for the shaft 2 to revolve to a point at which'contacts 23 and 24 are broken and contacts 23 and 22 are closed, is -suficient for the maximum number of impulses or steps to move, the wipersto the last group .of contacts. When this predetermined time .and a circuit is'completed between springs 22 and 23. iThe interruption between 23' and 24 has no efi'ect upon-relay '37 because at this time. the relay 34 is actuated by reason of the circuit being closed at the subscribers station, but a' circuit is completed through the impedance coil'39, contacts 23 and 22, conductor 47, contacts 4870f the primary off-normal set of springs, which are arranged to close upon the first-energization of magnet 46, through contacts 49 of the secondary ofi-normal set of springs and the coil of relay 50 to battery, thus actuating the relay 50. The actuation of relay 50' completes a circuit throughits. front contacts '51, interrupter contacts 52 and secondary stepping magnet 53to battery. The magnet 53 is adapted to move the contact wipers over the contacts of the group which has been picked out fby the previous actuation of magnetj46, the circuit 53 being made and.

broken by it's own conta'cts 52 so long asthe relay 50. remains in its actuated -cond1tion.

' Upon the first actuation of secondary magnet 53,-.the wipers 54 were moved into indicate the busy condition.

Considering that the-first few contacts to be reached by the private wiper 54 are thus guarded by a ground potential, a circuit is completed through conductor 55, front contacts 56 ofrelay 37, front contacts 57 and coil of relay 50 to battery. Current in this 'path maintains the actuation of relay 50,

which maintains the circuit through the secondary stepping magnet 53 until the private contact with the'firstof the series ofcontacts wiper 54 arrives upon a non-grounded trunk contact, whereupon the circuit in the path just described is interrupted and the relay 50 resumes its normal position, opening the circuitof the secondary stepping magnet 53 and closing its own back contacts 58, thus putting ground potential upon made by the controller 31 at the subscribers' station in designating the second digit of the desired number similarly deenergizes the relay 34 but this time, instead of controlling the circuit of the selector switch shown in the drawing, the circuit of the next switch in the series will be controlled. Primary magnet 46 and secondary magnet 53 are not actuated because their respective circuits arebroken through the opening of secondary off-normal contacts 45 and 49 as described above. As before, the electromagnet 15 will be energized by the first deenergization of relay 34, and at each dee'nergization of relay 34 a circuit will be completed through the back contacts 42, front contacts 43 of relay 37, conductor 44, back contacts 60 of relay 50, wiper 61, conductor 62 and a magnet of the next switch in the series. At the lapse of a predetermined interval as before described, contact 23 is moved from its normal connection with 24 and makes a momentary connection with contact 22, which completes a circuit through impedance 39, contacts 23 and 22, conductor 47, back contacts 63 of relay 50, wiper 64, conductor 65 and a relay or electromagnet of the next switch in the series to be controlled. This succeeding switch may be of the type disclosed in a patent to me, No. 975,608, of November 15, 1910.

In order to return the switch to its normal position, the circuit at the subscribers station is opened by replacing receiver upon.

what may be the hook, thus producing termed a long interruption.

Relay 34 then releases its armatures, which fall away, closing the back contacts 40 and 42. -Electromagnet 15 is, therefore, actuated as before described. At the end of a predetermined interval as provided by the action of ,the pallet 13, the circuit between contacts 23 and 24 is interrupted. This breaks the locking 37 and permits that relay to return to normal, closing its back contacts '66. A circuit is thus established through back contacts 42 of relay 34, back contacts 66 of relay 37, primary ofi-normal contacts 68 and coil of relay 50 to battery. The actuation of relay 50 again brings the secondary stepping magnet 53 into circuit, which, through its pawl, continues the movement'of wipers 54, 61 and 64 over the contacts until the switch has beenmoved to its extreme secondary position beyond the last contacts. in the group. At thispoint the primary retaining pawl is tripped, permitting the switch to return to its normal position so far as its primary movement is. concerned. At the end of this primary movement, the secondary retaining pawl is tripped, permitting the switch' to return to its normal position so far as the secondary movement is concerned. The interruption of contacts 56 of relay 37 removed the guard potential from private wiper 54, and

caused the release of the next succeeding switch in the series. Even before the release of the switch is accomplished, the shaft 2 hasfully completed its revolution and returned its contacts 22, 23 and 24 to their normal conditions. All of the apparatus is then returned to lts normal position and is in readiness for a second call.

It is to be understood that the apparatus of Figs. 1, 2,3 and 4 may be applied to many other types of system than that shown 1n Fig. 5, and that modifications may be made in the apparatus itself without departing from the spirit or scope of thisinvention.

What is claimed is:

1. In a telephone system, the combinationwith a telephone line, of an interrupter mechanism at the subscribers station of said line, a switch at the central oflice, a controlling relay for said switch under the com trol of said substation interrupter and a circuit changing device acting at a predetermined lapse of time after the first deenergization ofsaid controlling relay to change the circuit controlled by said relay.

2. In a telephone system, the combination with a telephone line, of an interrupter mechanism at the subscribers station of said line, a switch atthe central ofiice, a primary controlling magnet, a secondary controlling magnet for said switch, a controlling relay for said magnets under the control of said substation interrupter and a circuit changing device acting at a predetermined time after the first .denergization of said controlling relay to switch the circuit controlled by said relay from one of said controlling magnets to the other.

3. In a telephone system, the combination with a selector switch, a set of movable contacts for said switch and a plurality of sets of stationary contacts, an electromagnet for causing the step-by-step movement of the movable contacts to various sets of stationary contacts, a relay for controlling said electromagnet, and a circuit changer including an escapement mechanism also con- 5 trolled by said relay and adapted to remove said electromagnet from the control of said relay at a predetermined time after the first control of 'said magnet by said relay.

. mary magnet. a v

5. In an automatic telephone -systen1,-*tl1e' combination with a selector switch, of a pri -mary; controlling magnet and a releasing v 4. Jinan automatic telephone. system, the combination with a selector switch, of a primary controlling magnet and a secondary controlling magnet for said switch, a'

relay for controlling said primary magnet, a circuit changing device for bringing the secondary ma mined time a terthe first action ofthe primagnet for said switch, a relay initially causing the completion of the circuit of the primary magnet each; time it releases its 'arm'atu-res, and a switching device acting after a predetermined time from the release of the armatures of said relay to place the releasing magnet under the con-1 trol of said relay so as to return the selector et into action at a predeter-' switch to its normal position said relay is atthattime in its unactuated condition.

q 6. In an automatic telephone system, "the combination 'with'a central ofiice switch, of

circuit changing contacts for said switch, a controlling device, an electromagnet to set said device, spring actuated means for returning said device to normal, a controlling relay for said magnet, a circuit for, said magnet, closed upon the first deenergization ofsaid relay, means for delaying the return movement'oi-said device, said contacts be: --ing"-movedfrom and returned to normal during the" return movement of said device.

In witness whereof, I hereunto subscribe 35 

